STUFFING BOX SEAL Russian patent published in 2000 - IPC

FIELD: seals for shut-off fittings of hot water or steam condensate pipe lines. SUBSTANCE: proposed seal includes additional hold-down member located in stuffing box chamber which acts on packing; this member is made from thermosensitive material changing its volume at thermal action. Additional hold-down member may be made in form of kapron granules, rods, etc. in form of elastic ampoule filled with easily expansible or low-boiling liquid, in form of bimetallic washer or bush or in form of bush made from material possessing form memory effect, for example from nitinol. When not water is passed through seal, hold-down gets heated increasing in volume and packing is pressed to above-mentioned member at great force. EFFECT: enhanced operational reliability. 5 cl, 7 dwg